Binoculars and their Importance. (1 Viewer)

WJC · Mar 7, 2014

Odradek said:
Ahhh, Bush ist testing the newst coatings - not intended for civil use 3

Although I'm a conservative, I've never had a great affinity for some of George's goofs. HOWEVER, I've seen this photo used time and time again to show that he is an idiot in search of a photo op. This is NOT true!

He is holding a VERY expensive piece of stabilized night-vision gear by Varo. There are pin holes in those lens caps. They allow the instrument to be used in the daytime without destroying the image intensifier.

He is just doing what he would need to do under those conditions. In addition, he didn't make up anything with which to saddle any member of BF. |=)|

OPTIC_NUT · Mar 7, 2014

Snopes has two alternate theories: pinhole daylight use and anti-reflective front cover.

WJC · Mar 7, 2014

OPTIC_NUT said:
Using night gear with intensifier tubes in daylight...with a pinhole?
That is bizarre. It can't have very good resolution....with a pinhole.
For training? How big is the pinhole?

I don't recall repairing any that didn't have a pinhole. Also with the light being "intensified" several thousand times, not all theories that apply to conventional optics apply. But keep in mind that the pinhole makes the effective f/R huge.

Size? Probably about .020-.025. THAT'S SHOOTING FROM THE HIP! I can't say I remember.

Bill

WJC · Mar 7, 2014

OPTIC_NUT said:
Snopes has two alternate theories: pinhole daylight use and anti-reflective front cover.

I will see Snopes' anti-reflective covers and raise them an:

I worked on the darn things.

Bill

OPTIC_NUT · Mar 7, 2014

The confusing part is...the way pinholes affect the resolution.
That, and the tubes. The gist is: would the resolution be very poor
compared to binoculars in daylight? If it was some sort of training method
and the gadget's resolution was coarser than the pinhole's it would add up correctly.

Like....it's day and you're showing the President what it would look like at night..maybe.

ronh · Mar 7, 2014

S'prise, s'prise, as Gomer used to say! Welcome Bill! I note with discomfort that you are not merely still alive but making us think now, ouch.

I'm with Optic Nut in that I think, no way with a single pinhole unless it was a mighty big "pinhole" and the magnification was about 1x. But more than one tiny pinhole might work at normal binocular magnifications.

If there was a ring of pinholes at some reasonable radius, 10 mm say, there would be a spike in the transfer function at a fairly high angular frequency that just might get you by in a pinch, but oh man what a screwy view it would be. Randomly scattered pinholes would probably give the best "most natural" view per summed pinhole area.

How were the pinholes configured Bill?

Ron

David in NC · Mar 7, 2014

NV Optics have these in many cases.

Here is a PVS7 NVD lens cap:

http://www.optics4birding.com//item.aspx?cid=22232&utm_source=GoogleShopping&utm_medium=organic&zmam=45392963&zmas=1&zmac=1&zmap=22232&gclid=CKf-65Hi_7wCFeRi7AodKwMAmQ

WJC · Mar 7, 2014

David in NC said:
NV Optics have these in many cases.

Here is a PVS7 NVD lens cap:

http://www.optics4birding.com//item.aspx?cid=22232&utm_source=GoogleShopping&utm_medium=organic&zmam=45392963&zmas=1&zmac=1&zmap=22232&gclid=CKf-65Hi_7wCFeRi7AodKwMAmQ

BLESS YOU DAVID! Now I don't have to reinvent the wheel--I can go to bed!

Ron, I'll catch you tomorrow.

So David: does my pinhole description match what I told them? :t:

Cheers,

Bill

David in NC · Mar 7, 2014

WJC said:
BLESS YOU DAVID! Now I don't have to reinvent the wheel--I can go to bed!

Ron, I'll catch you tomorrow.

So David: does my pinhole description match what I told them? :t:

Cheers,

Bill

Yep. I'm a former NC Army National Guard member and career cop and the later NVD stuff (as I recall) usually has the pin holes. I was always told it was for merely TESTING the device (s) during daylight hours to assure it was working (?) Sounds reasonable-it's not for using during daytime as conventional optics.

WJC · Mar 7, 2014

David in NC said:
Yep. I'm a former NC Army National Guard member and career cop and the later NVD stuff (as I recall) usually has the pin holes. I was always told it was for merely TESTING the device (s) during daylight hours to assure it was working (?) Sounds reasonable-it's not for using during daytime as conventional optics.

No, but it can be done for short periods. I have worked on thousands of the AN PVS 7s. The old Vietnam stuff is more fun . . . it decomposes as you work on it!

Cheers,

Bill

OPTIC_NUT · Mar 7, 2014

Diffraction-limited issues at the size....but the depth of field would be out of this world.

I'd go with, "showing the President what night ops look like, sorta".

Pinewood · Mar 7, 2014

OPTIC_NUT said:
Diffraction-limited issues at the size....but the depth of field would be out of this world.

I'd go with, "showing the President what night ops look like, sorta".

Hello Optic Nut,

Once, I used an old Polaroid camera, which had very fast film. For daylight use, the lens cap had a pinhole. As you suggested, the depth was terrific but the resolution was poor.

Happy bird watching,
Arthur Pinewood :hi:

WJC · Mar 7, 2014

Hey Art:

Waiting for CN to come back online?

WJC (BillC)

Pinewood · Mar 9, 2014

WJC said:
Hey Art:

Waiting for CN to come back online?

WJC (BillC)

Hello BillC,

It is already online, but I hardly use binoculars for astronomy. I am generally disappointed in those who post to that site, as they often seem to be unable to tell the difference between a$50 and a $500 binocular. Most people on BirdForum, appreciate good optics and have little to do with do it yourself.

My name is not Art.

Happy bird watching,
Arthur Pinewood

WJC · Mar 9, 2014

Pinewood said:
Hello BillC,

It is already online, but I hardly use binoculars for astronomy. I am generally disappointed in those who post to that site, as they often seem to be unable to tell the difference between a$50 and a $500 binocular. Most people on BirdForum, appreciate good optics and have little to do with do it yourself.

My name is not Art.

Happy bird watching,
Arthur Pinewood

Woah! Sorry Arthur; I didn't know you were sensitive.

Here in Lake Stevens we have a FEW Stellars Jays . . . and a bunch of noisy crows. For the first few years, we were in the area, we had plenty of VG Swallows and Barn Swalllows. No more! Then, we had two years of the migrating Waxwings. Since then--nothing except the resident Jays and crows.

If you want to see a pretty bird, you have to buy a magazine! |=)|

Bill

mooreorless · Mar 10, 2014

Odradek said:
Ahhh, Bush ist testing the newst coatings - not intended for civil use 3

I think not!

http://www.snopes.com/photos/politics/binoculars.asp

Pinewood · Mar 11, 2014

WJC said:
Woah! ...

Here in Lake Stevens we have a FEW Stellars Jays . . . and a bunch of noisy crows. For the first few years, we were in the area, we had plenty of VG Swallows and Barn Swalllows. No more! Then, we had two years of the migrating Waxwings. Since then--nothing except the resident Jays and crows.

If you want to see a pretty bird, you have to buy a magazine! |=)|

Bill

Hello BillC,

You should come to the big city to see pretty birds. Today's sightings in Central Park included an American woodcock, cedar waxwings, a blackcapped, chickadee, downy and red bellied woodpeckers, white breasted nuthatches, brown creeper,s a cooper hawk, a female Baltimore oriole and a song sparrow.

Happy bird watching,
Arthur Pinewood

WJC · Mar 21, 2014

Today was the first day of Spring. I know because each year, (the last 4 years) at this time, a woodpecker starts hammering away at the flashing around our chimney, leaving no place of rest in the house while he's at it.

Anyway, Arthur, as was going downstairs this morning to take my 4-legged son for a walk, a bird smashed into the middle of my living room's picture window. He hit it hard and I just KNEW he had dead. Going to the window, I noticed a dazed Northern Flicker walking around the yard.

Giving him time to recoup, I opened the door to take the dog out, and he flew into a nearby tree. Going to my dog's favorite tree, I noticed his mate.

So much for never seeing an new pretty birds.

Bill

OPTIC_NUT · Mar 21, 2014

Pinewood said:
Hello BillC,

You should come to the big city to see pretty birds. Today's sightings in Central Park included an American woodcock, cedar waxwings, a blackcapped, chickadee, downy and red bellied woodpeckers, white breasted nuthatches, brown creeper,s a cooper hawk, a female Baltimore oriole and a song sparrow.

Happy bird watching,
Arthur Pinewood

And then some...!
Central Park is an extremely strategic and special migratory node,
and has a big birdwatching community. I'd consider it a key
reason for tourism. The movie "Birders: The Central Park Effect" is a
window on that. It's incredible what flows through in a year.
We can get a lot of that in NE Mass., but not all in the same day!

Plenty in the museums, too, to get down to the last arc-second. ;-)

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